Simone van der Vlugt 
Shadow Sister 

Gripping psychological suspense, perfect for fans of Nicci French.Married. One child. A career: Lydia has her life in perfect order — if only everyone else around her could be as organised as she is. Her unmarried twin sister Elisa is still struggling to find what she wants to do. And her colleagues at the school where she teaches often fail to reach her high standards.But one day, it all falls apart from Lydia. When she is threatened by one of her pupils, her sister is the first person she turns to. But Elisa is powerless to stop the campaign of intimidation that follows. How far will it go? Or is someone else taking advantage of the situation? And what is Elisa’s part in all of this? Twins are close. Aren’t they?